SFX 's sister magazine Science Uncovered explains how antimatter could power starships
But scientists are now just learning how to create antimatter in meaningful amounts – to understand it's properties and to learn how it might be used to propel spacecraft to other solar systems.
In the March edition of SFX 's sister mag, Science Uncovered , renowned science writer Marcus Chown looks at the research now taking place on antimatter and just how likely a fuel source it is. Here's a sneek peek at a snippet of his article:
Even the nearest stars are an immense distance away. If a spaceship is to reach them in a reasonable time, it will need to accelerate to an appreciable fraction of the speed of light, which is about a million times faster than a passenger jet. Unfortunately, this requires a lot of fuel, which adds to the mass of a spacecraft, making it even more difficult to push.
The annihilation of antimatter and matter unleashes the most energy, pound for pound, of any known fuel – 100 times more than any conceivable nuclear fuel. “Antimatter would be an excellent fuel for travel within the Solar System and to nearby stars since it is a way of storing energy in a very light and compact form,” says Physicist John Cramer of the University of Washington in Seattle.
The proviso, says Cramer, is “if the tech problems could be solved”. Those “tech” problems include finding a cheap way of producing and storing antimatter. “This will require significant technological progress,” says Cramer. For one thing, producing antimatter fuel would be an immense undertaking. “At current rates of production, it would take more than the age of the universe to make a gram,” says Professor Jeffrey Hangst at CERN . “And you’d have to put infinitely more energy into making it than you would ever get out.”
Another formidable problem is storing antimatter on board a spaceship without any leakage. If it did leak, it would be catastrophic.
Then there is the problem of how precisely you would use matter-antimatter annihilation to create a "rocket effect." This requires any subatomic shrapnel produced in the annihilation to be ejected in one direction so that the spaceship, obeying Newton’s Third Law, is pushed in the opposite direction. The problem is that annihilation products – short-lived particles like "pions" – spray outwards in all directions. So some kind of super-strong magnetic field would be needed to direct them in one direction. “It would work only for the charged particle,” says Hangst. “And it would have to be one hell of a magnetic field.”
If all of these problems are eventually solved – and there is no reason to assume they can't be – as Cramer points out, there is one more significant fly in the ointment. “A trip to a nearby star would very likely require more than a human lifetime,” he says.
But antimatter annihilation is faster than any propulsion system we have right now. And with over 200,000 people applying to be part of Mars One Foundation 's one-way trip to the Red Planet, it looks like there would be no shortage of volunteers to sign up for the ultimate adventure – to other solar systems.